Thread: DLL trouble

  1. #1
    Registered User
    Join Date
    Aug 2007
    Posts
    2

    DLL trouble

    Hi, I am using Dev-C++ and I made my first DLL. The DLL added two numbers together and returned the sum. I tried to send a string and have it send it back but for some reason it just sends back nothing. Here's my code...

    dll.cpp
    Code:
    char* DllClass::String(char* string)
    {string = "Hello World";
    return string;}
    dllclient.cpp
    Code:
    int main()
    {
    char* iValue;
    char* vReturn;
    DllClass Value;
    cin >> iValue;
    vReturn = Value.Encrypt(iValue);
    cout << vReturn;
    system("PAUSE");
    }
    Keep in mind the DLL works when dealing with numbers, so I'm not sure what the problem here is... Thanks anyways.

  2. #2
    Sweet
    Join Date
    Aug 2002
    Location
    Tucson, Arizona
    Posts
    1,819
    You can't just assign a string like that. You would need to use strcpy.

  3. #3
    Hurry Slowly vart's Avatar
    Join Date
    Oct 2006
    Location
    Rishon LeZion, Israel
    Posts
    6,794
    cin >> iValue;

    iValue is not initialized pointer... You just asking from the cin to write the input data on some random address...
    All problems in computer science can be solved by another level of indirection,
    except for the problem of too many layers of indirection.
    David J. Wheeler

  4. #4
    Registered User
    Join Date
    Aug 2007
    Posts
    2
    Hmm I'm sorry I don't think I understand. If you could by any chance show me the code you think I should use to get the Dll code to return the string to the exe. Thanks again :\

  5. #5
    Registered User
    Join Date
    Oct 2001
    Posts
    2,934
    dll.cpp
    Code:
    std::string DllClass::String(std::string string)
    {string = "Hello World";
    return string;}
    dllclient.cpp

    Code:
    int main()
    {
    std::string iValue;
    std::string vReturn;
    DllClass Value;
    cin >> iValue;
    vReturn = Value.String(iValue);
    cout << vReturn;
    system("PAUSE");
    }

Popular pages Recent additions subscribe to a feed

Similar Threads

  1. non-MFC DLL with MFC app question.
    By Kempelen in forum Windows Programming
    Replies: 10
    Last Post: 08-20-2008, 07:11 AM
  2. Replies: 1
    Last Post: 09-18-2005, 09:06 PM
  3. dll communicating between each other
    By cloudy in forum C++ Programming
    Replies: 5
    Last Post: 06-17-2005, 02:20 AM
  4. DLL and std::string woes!
    By Magos in forum C++ Programming
    Replies: 7
    Last Post: 09-08-2004, 12:34 PM
  5. .lib vs .h vs .dll
    By Shadow12345 in forum C++ Programming
    Replies: 13
    Last Post: 01-01-2003, 05:29 AM